Please provide a brief comment on He Jiang's commencement speech at Harvard University. The comments rang from 80 words to 150 words. Please comment on the speech from the following aspects: 1. topic; 2; structure; 3. beginnings and endings; 4. language; 5. delivery and effect. Please try to give more specific comments. You can also share some your favorite ideas from his speech. Pay attention to the question: How does he tell China story from a youth perspective? How does he connect his topic with the audience? speech link https://www.bilibili.com/video/av928355997/